GLOBAL
WARMING DAYS & TIMING THE BEAUTIFUL FLOWER
Obviously the time a cultivar takes for a tiny shoot to produce a good stem and
a full flower varies from cultivar to cultivar. The showmen get to know the
dahlias they use, and can tell within a few days how long that period will be,
but with new and as yet untried seedlings it becomes slightly harder. Most of
the top growers hold all this valuable information in their heads, so add to
this fact the number of plants of each variety they handle, and is it any wonder
they will have sufficient flowers to select a winning vase or three on show day.
In my case all I want to do is have the new flowers ready for the seedling
classes at the NDS show at Shepton Mallet unlike last year. Another favourite
place to show them off is at Wisley when the RHS and NDS joint committee meet as
this is about the furthest I can go without friendly assistance. Of course
should I have flowers ready when a show is being held fairly near I’ll be there
providing there are seedling classes. A very rough estimate for bloom
development would be eight weeks from when the plant is either stopped or cut
back, but of course the bigger the flower the longer it takes. Cutting back has
been given the nickname “Knock back” a pretty good description as some times the
early plant is hacked down to within several inches of the ground. As Dave
Spencer told me when I approached him about the subject, “You’ve got to be brave
because you are relying on the root system the plant has made up to that point
to produce the stems of the next set of flowers” I was a bit apprehensive when I
ran Dave because guys such as he must get thoroughly sick and tired of continual
phone calls, but far from it, he explained the act of `Knock Back’ exquisitely
,and I gained a very important piece of advice for the cost of a phone call. I
should imagine attending a lecture by this man would be worth its weight in
gold. Of course it will mean experimenting regards the actual date the deed is
done, but let’s say if I don’t succeed on the first occasion I’ll adjust my
times and try again the following year. Like us humans, every variety has its
particular trait, so beware, and expect surprises. Another thing that affects
timing is of course the weather; the summer of 2006 bore this out with flowers
opening far too quickly to the detriment of the finished bloom. So while the bud
or bloom is developing, and the weather is over cast it will slow the flowers
development down, this is obvious. A great email friend of mine in Australia
called John Menzel has studied this to such a degree he could tell you within
ten minutes when a particular bloom could be at its peak showing stage because
he knows his subject and the area he lives in. He uses varying degrees of
shading when the blooms are opening, but then this is Australia, and of course
with their continual sunshine if this wasn’t done he would have no blooms at
all.
The next important moment in the development of a dahlia plant is, at what stage
do you secure the bud? Dis-budding and securing the bud is the last stage that
can influence the time each flower takes to open, get this wrong at your peril,
it makes the difference of having flowers for that particulate date or not, it’s
as simple as that. I have in the past run on stems to the next bud, but never
found it to be satisfactory; most times the resultant blooms are light of petal
perhaps I don’t feed enough? In case you don’t already know about dis-budding
let me explain, you have a cluster of buds at the end of the stem, and each will
if left to nature open at specific times. If you take the centre bud, this will
open earlier than the side bud by about a week, this bud is often called a wing
bud, so it is obvious that buds lower down will open progressively later, the
further down the stem you go the later the bloom will be. Of course if you go
right down, you are approaching the “Knock back” situation again, but at this
stage in the year it would be too late for all but the very last shows. I am not
a showman, not in the strictest sense of the word, I like showing off, but
that’s a different matter. So for anyone in a similar position to me, here are a
few dates I have worked out. I haven’t got any particular theory it is just a
rough guide for each group.
The hardest to my mind to judge are the giants; well you only get one crack at
them, bit like an early flowering chrysanthemum. So if you miss the date you’ve
got another twelve months to wait. As I have only raised one reasonable giant
called Argyle Gold Top, and I don’t consider it good enough to beat the very
best at this stage I don’t have to worry because the only place Argyle Gold Top
will be growing will be on Bob Hendley’s dahlia field at Sturminster Newton.
However for the benefit of anyone who didn’t read the excellent article written
by Wayne Holland a year or two back called “Chasing the Bud” here are the bones
of the article. Instead of taking the buds nearest the central bud the whole
process is started a little earlier and the shoots lower down are removed at a
very minute stage. This induces the sap to fill out the up portion of the plant,
and in turn produce a heavier stem to support a larger flower. In other words
you start from the other end. Of course the side buds next to the main bud
should not be left to long or the concept is wasted. I should think it works on
giant’s best, but it could be used on any group I suppose. Now let me give you
my rough guide for securing the buds of all groups, and the number of days it
takes from securing the bud to the show date, then there will be every chance
you’ll be able to put up a vase or two, and more vases mean a better show, but
remember the location you live in is the biggest factor of all which includes
the aspect of the ground.. For you experts and I know we have a few in our
midst, go and make a cup of tea.
Starting with the giant’s they can take up to 50 days. Large would be nearer 40
days. Medium could take say 30 days. Smalls down to 25 days and miniature’s 20
days. I haven’t worked out the timing of the Collerette’s yet, but they open so
fast that like the good ol’ London buses if you miss one another comes along
very quickly. Now count back the days from the show you wish to exhibit a
particular group in, and secure your buds around the date it falls on,
remembering to have some buds a few days either way. Now that’s about all you
can do regards the timing of your plants, but there are other things you can do
to delay them when the buds are taken. Nothing now will make them sooner than
their time clock will allow, except of course if the weather turns warm and
sunny, but we don’t want it to be to hot when the flowers are opening, or they
will open to quickly loosing quite a bit of colour, and substance. So in order
to protect the colour especially the darker ones and delay flowering a little
why not use a shade cloth. You can build an impressive compound like John
Menzel, or be like me and opt for a simple over head affair made up of bamboo
canes. Of course it has to be strong and secure enough to take a battering, but
being light and strong it will have an advantage, remember a Willow can bend.
Fortunately I don’t live in an exposed area out in the `Bush’ like John Menzel
does at Winkie.
A 30% shade cloth will not only delay flowering and protect the colour, but it
will also put a few more inches on the height of the plants, and as many of you
grow in town like me you know that your plants are already over a foot or more
higher than they would have been in a field position. So remember this, and try
to arrange that on dull days this shade cloth can be drawn back like the lounge
curtains. The only difference is these nets will be at a forty five degree angle
and some distances from the plants so the shade is thrown on to the blooms
without actually being over them, the operation is also meant to divert the
winds power over and away from the developing blooms as well as giving them the
shade they need, least that’s the theory. Of course I could have made covers
similar to the ones I had when I exhibited early flowering chrysanthemums, but
as the dahlia flower is well able to stand any amount of rain it seems pointless
to cover them completely as the only place they’ll be shown is in a seedling
class or at Wisley when the Executive Committee meet, but of course when this
season is over I may well change my tune.
I’m purposely missing out anything to do with feeding, sufficed to say if you
have your soil well nourished, and have built up a reasonable fertile
environment a good base dressing and a few weak liquid feeds will hone them to
show potential. If however your ground isn’t in good heart a few more liquid
feeds won’t go a miss. Learn to, as John Menzel often says `Read Your Plants’
because when you see a good vase of flowers you will almost certainly see a good
vase of leaves, most of this comes from experience, and of course the more
intelligent you are the quicker you pick it up, must be why it’s taken me so
long to get it right, but no matter what species you grow the leaves on it will
tell you all.
Question, what influences the growth of a plant more than any thing else, and
I’ll give you a clue “Last year we didn’t have much” correct rain. It’s hardly
surprising that this would affect growth considering the dahlia plant is made up
of about 80% water, some say more. I’d have questioned this a few years back,
but after not being too good after getting the tubers up a year or so ago the
mountain of old discarded tops had to be left where they were for some
considerable time. Consequently when I felt like getting shot of them they had
diminished to a manageable heap. Of course when we water there are different
methods used, the hand held hose in the right hands is okay. I know I’ve been
doing it this way for many years, and although it’s time consuming you can give
the plant the right amount, but since the John Menzel article I wrote describing
a typical Australian dahlia season in his region I’m sure the method I use, and
most likely the way you do it can be done not only more efficiently, but in a
way that benefits the plants we grow. Add to this the savings on our valuable
water supply, and it becomes the right thing to do. The things mankind does of
course has an affect on our climate, but I don’t think it is quite as much as
some are trying to make out, none the less anything we can do to help the world
to clean up the mess we make must be a plus. So I’ll leave it to those in charge
to find out what we should be doing, and the boffins to write about it and get
pulled over the coals for.
Okay you ask, come on clever clogs what’s this revolutionary way of watering?
Well like the blood goes round your body, so the water needs to circulate around
and into our plants. The word is `Pulse’ the tubing used is called a `Drip Line’
which has built in valves at roughly twelve inch intervals along its entire
length. These valves can become blocked when used for supplying the plants with
anything other than water, or if sandy particles run through the system. The
remarkable thing is they unblock their selves by a coughing motion within the
valve it self.
Of course the more plants you grow the more `Drip Lines’ you will need, and the
more expensive it will become to use them, but anyone with a modicum of DIY
skills could install this simple answer to our water troubles. Once install a
programmer on the tap will do the rest. I’ve looked at most types and eventually
chose Hozelock’s Aqua Control C4 which gives four programmes a day of anything
up to an hour long, but as we’re not growing Watercress mine will be set at a
fifteen minute duration four times a day. John Menzel assured me in Australia
with their diabolical growing conditions, he waters for a very short time
compared to using a hand held device. I for one believe him, and I’m completely
sold on the whole idea. It seems to me if I give my charges only four
applications the total water saved will be enormous, and of course supplying a
good mulch and shade cloth will help the evaporation loss. The beauty of the
idea is this, it puts moisture were the plant can use it at that particular
time, and no more than eighteen inches down in that vital root area. As no water
is applied to the foliage this to my mind could delay the appearance of downy
mildew when conditions are rife, and while we are watering a liquid fertilizer
in a weak state could be given to the plants if an in line feeder is present at
some point before the moisture gets to the plants. In these unusual times when
weather patterns are constantly changing anything that can make the growing of
our beautiful flower easier should be grasped with both hands. So this is what I
will be doing this year to get my seedlings to Shepton Mallet, and like all
enthusiasts I’m refreshed and raring to go once more, but only time will tell if
all this beats what our forefathers have been doing for centuries. Oh the title?
I wanted to grab your attention that’s all.
See you at the trials.